The prior art, U.S. Pat. No. Des. 202,053, discloses an ornamental design for a loop track for toy vehicles.
Additionally, U.S. Pat. No. 3,677,469 discloses an accessory for a track system useable with toy wheeled vehicles which serves to change the direction of travel of vehicles traversing the track while at the same time causing the vehicles to travel through an essentially vertical loop. The track system utilizes well-known linear sections of elongated flexible track and includes a loop-turn fixture having track securing members which serve to secure the track to the loop-turn fixture.
U.S. Pat. No. 3,696,557 discloses a self-propelled toy including a hollow shell and a battery-operated motor which is enclosed within the shell for causing the shell to roll along a supporting surface. A gravity-operated switch is mounted on the motor for de-energizing the motor when the toy is not in use. In operation, the motor is disposed at a lowermost portion of the shell, and the switch is disposed in a position to energize the motor for causing the shell to revolve about the motor. When the shell becomes restrained from movement, the motor moves relative to the shell along the inner surface thereof until the switch reaches a position where it opens the circuit to the motor.
U.S. Pat. No. 4,146,991 discloses a toy trackway featuring a platform having an upper level and a lower level; the upper level is provided with a trackway terminating at each end in a locking member, and the lower level is provided with two trackways, each terminating in a locking member. Two flexible trackways each terminate in locking members for engagement with the locking members of the trackways on the upper and lower levels of the platform, thus permitting one of the locking members of each of the flexible trackways to be attached to the locking members of the trackway of the upper level and the other of the locking members of each of the flexible trackways to be attached to the locking members of the trackways of the lower level either on the same side of the platform or on opposite sides of the platform.
U.S. Pat. No. 4,251,949 discloses a toy racing apparatus including an inclined section of track and a bowl. The track enters the bowl through an opening in the lower sidewall where its surface is tangent to the interior wall. A vehicle placed at the upper end of the track will speed down the track, enter the bowl and progress in a spiral path upwardly inside the bowl. In a preferred embodiment, the bowl is transparent and flags are positioned to be displaced as a vehicle reaches particular heights in the bowl.
U.S. Pat. No. 4,285,157 discloses a toy racing set including at least one powered vehicle, a length of flexible track and a carrying case. The carrying case folds out to form a track upon which the vehicle may run. The case may also be used when closed with the flexible track to provide a loop-the-loop track for a powered vehicle.